Faster and more powerful computer components allow the design and construction of higher performance portable computing devices such as laptop or notebook computers. Unfortunately, the use of such faster and more powerful computer components often results in increased heat generation by such computing devices. Thus, improved heat dissipation technology is often needed to maintain operating temperatures of portable computing devices within the same range as their predecessors or some other acceptable range.
A portable computing device typically includes a base and a screen which are rotatably attached by a hinge. The base usually has an input device such as a keyboard or a touchpad as well as a number of electronic components. Integrated circuits with the highest clock frequency are typically located in close proximity to each other within the computer base.
Many heat generating computer system components take the form of integrated circuits. Such integrated circuits are typically mounted on a motherboard or another circuit board within the base the portable computer system. A processor is one component that generates a large amount of heat in a typical processor system. Other electrical components which also generate heat include memory circuits, power supply circuits, and circuit boards such as video card.
Maintaining operating temperatures of computer system components below certain levels is important to ensure performance, reliability, and safety. Most integrated circuits have specified maximum operating temperatures, above which the manufacturer does not recommend operation. Transistors, the building blocks of integrated circuits, tend to slow down as operating temperature increases. Thus, a computer system that operates its integrated circuits close to or beyond recommended timings may fail as temperature increases.
Additionally, integrated circuits may be physically damaged if temperatures elevate beyond those recommended. Such physical damage obviously can impact system reliability. Finally, the computer system casing should be kept at a temperature which is safe for human contact. This may necessitate spreading of heat throughout a computer system base or efficiently expelling heat to avoid hot spots near certain components such as a processor.
Typically, heat sinks, fans, and heat pipes are employed to dissipate heat from integrated circuits and other electronic components. Increases in heat generation are often accommodated by simply increasing the quantity or size of these heat dissipation elements. The relatively small size of a portable computing device, however, complicates heat dissipation by limiting airflow, crowding heat generating components, and reducing the space available for heat dissipation devices.
Since the computer base size is generally kept to a minimum, and the computer base contains both the input device and numerous other electronic components, there may be inadequate space to dissipate enough heat to keep the electronic components within their acceptable range of operating temperatures. Additionally, heat dissipation through the bottom of the base is limited because the computer is usually operated on a relatively flat low conductance surface.
One prior art method for removing heat from the base of a portable computing device involves transferring heat from the base of the device to the display. The technique of transferring heat to the display is limited due to the thermal and mechanical difficulties involved with transferring heat through the hinge of the computing device. Additionally, using this technique, all of the heat is dissipated by the portable computing device.
A docking station is a well known computer attachment that mates with a portable computer to allow the portable computer access to various peripheral devices. Typically, the base of the portable computer plugs into a larger monitor and a full size keyboard. This advantageously allows a portable computer user to operate a portable computing device in a more ergonomic desktop computer setting rather than using a small keyboard and screen as is typically provided in a portable computing device.
The portable computer is often guided into the docking station by alignment rails, and docking pins from the docking station engage a mating connector at the rear of the portable computer. Electrical receptacles from either the docking station or the portable computer engage mating connectors from the other device.
Mating a portable computing device with a docking station often compounds the difficulty of cooling portable computing devices because the display is typically closed. This reduces the natural or passive cooling capability of the portable computing device because convective airflow over the top of the base is mostly blocked by the screen.
The prior art does not take advantage of additional cooling capacity available from components such as a docking station with which a portable computing device may be mated. Particularly, the prior art does not provide a heat dissipation solution which utilizes docking station resources to enhance airflow through the portable computing device.